Abstract: The geopolymer solidification technology is used to treat the radioactive fluoride liquid waste generated during the operation of thorium-based molten salt reactors. Water glass(sodium silicate aqueous solution) and fly ash were used as raw materials for geopolymer solidification of simulated radioactive fluoride liquid waste. 16 groups of geopolymer solidification formulas were formed by designing orthogonal experiment with four factors and four levels. The geopolymer solidification forms were maintained at 60 ℃ for 28 days, and its compressive strength, immersion resistance and leaching resistance were investigated. The results show that when the water glass modulus is 1.5, the water cement ratio is 0.35 or 0.40, the alkali activator mass fraction is 30% and the F⁻ mass fraction is 4%, the compressive strength of geopolymer solidification form is 47 MPa, and the loss of compressive strength after 90 days of immersion indeionized water at (25±5) ℃ is 13.75%, the Co²⁺, Sr²⁺ and Cs⁺ leaching rate on the 42^nd day and the cumulative leaching fraction meet the requirements of GB 14569.1—2011. The leaching concentration of F⁻ on the 42^nd day is 2.81 mg/L, which is lower than the limit requirement of GB 5083.3—2007 (100 mg/L). It can be seen that the formula achieves effective solidification of simulated radioactive fluoride liquid waste. The effects of maintenance conditions(including temperature, humidity and time) on the performance of geopolymer solidification form can be further explored in the future, with a view to providing a proven technical route for the stabilization treatment of radioactive fluoride liquid waste.